Automatic eraser for type-writers.



F. A. JOHNSON,

AUTOMATIC ERASER FOR TYPE WRITERS.

APPLICATION FILED APR. 14. I917.

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Specification of Letters Patent.

Patented May it, i9l8.

Application filed April 14, 191,7. Serial No. 162,132.

To all whom it may concern:

Be it known that L'Fnnnn A. Jonnsorr, a citizen of the United States, residing at UniversityPlace, in the county of Lancasten and provide a typewriter eraser which is adapted to be swung from an inoperative to an operative position and then automatically revolved to erase one or more letters from the paper positioned around the platen.

Another object of the invention is to pivotally attach a supporting arm to the typewriter and to provide a keypositioned within the usual key board which when depressed will swing the supporting arm to a position adjacent the platen, spring power means being provided to automatically begin revolving the eraser, carried by the support ing arm, just prior to its reaching its opera tive position, and when the key is released the power means will become automatically inoperative and thus prevent further rota of an automatictypewriter eraser attached thereto, and

Fig. 2 is a vertical sectional view taken on the line 22 of Fig. 1.

Similar characters of reference are used to denote like parts throughout" the accompanying drawings and the following description. v

Referring more particularly to the drawings the reference numeral '1 indicates a tubular supporting arm which is provided with a downwardly extending lug 2 that is pivotally attached "as at 3 to a clamping member 4 secured to the front portion 5 of v the typewriter frame. This tubular supporting arm is also provided adjacent its inner end with a laterally extending ear 6 to which is secured one end of a flexible ele-; ment 7. v

Z A flexible shaft 8 is extended through and journaled in the tubular supporting arm 1, and connected to the outer end of the shaft is a revoluble typewriter eraser 9.

Attached to one side of the typewriter frame in any suitable manner is a gear casing 10 in which is mounted a coiled tension spring 11 secured to and wound around a rotatable shaft 12, the outer free end of the spring being secured to the casing as at 13. The outer end of the shaft 12 is provided with a'key 14 by which the spring may be wound up.

Extending transversely of the casing 10 and adjacent its forward end is a rotatable shaft 15 which is revolved from the shaft 12 through the medium of a suitable train of gears interposed between them. A bevel gear 17 is fixed on the shaft 15 and meshes with a similar gear 18 secured to the lower end of a vertically disposed shaft 19, which is journaled at its lower end in a bearing 20 and at its upper end in a bearing 21. The opposite end of the flexible shaft 8 is rigidly attached to the upper end of the shaft 19.

Arranged within the typewriter frame is an. actuating key 22 which consists of an angular arm pivotally mounted at its inner end as indicated at 23 to the casing 10 or to the typewriter frame as found most convenient.

In order to prevent the flexible shaft 8 from constantly revolving l have provided brake mechanism which consists of a disk 24; fixed on the shaft 15, and with which a brake shoe 25 carried by a supporting arm26 is designed to frictionally engage and prevent rotation of the disk. The inner end of the arm 26 is pivotally mounted within the easing as at 27, and'anranged below the arm is a leaf spring 28 designed to bear against the arm and hold it in frictional engagement with the disk.

The outer end of the arm 26 is provided with a laterally projecting pin 29 which projects through the arcuate slot 30 in the It is also to be noted thatthe flexible element 7 is continued from the ear 6 over a pulley 31 and then downwardly and connected to the key arm 22.

. From the foregoing construction it will be apparent that when it is desired to erase. a letter or character from the paper positioned around the typewriter platen, it is simply necessary to depress the key 22 which will swing the supporting arm 1 and the eraser 9 into the dotted line position shown. As the key 22 is depressed it will release the brake shoe 25 from the disk 24 just prior to the time when the eraser 9 reaches its operative position so that by the time the eraser has reached its operative position it will be revolving to effectively erase the desired character from the paper. Immediately upon the releasing of the key 22, the eraser will cease revolving and be subsequently swung to an inoperative position.

It will of course be understood that the cleaning efficiency of the device will depend to a great extent upon the rapidity at which the eraser revolves, therefore it is to be understood that any size or proportion of gears may be used in the train of gears interposed between the shafts 12 and 15.

It is also to be noted from the foregoing description that by the arrangement and construction of this device that the hands of the operator need not be removed from the typewriter key board in the operation of the device and that. the device will not in any way interfere with the visibility of the written words or characters. It is also to be understood that such changes in form and arrangement of parts may be made as are necessary to attach the device to the various makes of typewriters, without departing from the spirit of the invention.

What I claim is 1. The combination with a typewriter, of an eraser, means for swinging the eraser from an inoperative to an operative position, and spring power means adapted to be released by said eraser when in an operative position.

2. The combination with .a typewriter, of

a supporting arm pivotally attached to the typewriter, a revoluble eraser carrier by the supporting arm, means for swinging the supporting arm horizontally from an inoperative to an operative position, and automatic means for revolving said eraser when released for operation by said arm swinging means when'swung to an operative position.

3. The combination with a typewriter, of a supporting arm pivotally attached to the typewriter, a revoluble'eraser carried by the outer end of said supporting arm, an actuating key pivotally supported by the type writer, a flexible element connecting said supporting arm with the actuating key,

whereby the eraser may be swung from an inoperative to an operative position upon the actuation of said key, and means for automatically revolving said eraser when swung to an operative position.

4. The combination with a typewriter, of a supporting arm pivotally attached to the typewriter, an eraser revolubly supported by said supporting arm, an actuating key pivotally supported by the typewriter, a flexible element connecting said supporting arm with said actuating key whereby the eraser may be swung from an inoperative to an operative position, and power means adapted to be released by the actuation of said key to revolve the eraser when in operative posi tion.

5. The combination with a typewriter, of a tubular supporting arm pivotally attached upon the typewriter, a flexible shaft disposed through and journaled within said supporting arm, an eraser fixed to the outer end of said flexible shaft, means for swinging said supporting arm and eraser from an inoperative to an operative position, and power means connected to said flexible shaft and adapted to automatically operate to revolve the eraser when the eraser has been moved to an operative position.

6. The combination with a typewriter, of an eraser, means for swinging the eraser from an inoperative to an operative position, spring power means for revolving said eraser, brake mechanism for said spring power means, said brake mechanism adapted to be released by the actuation of said swinging means to permit the eraser to revolve when in operative position.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

. FRANK A. JOHNSON.

Witnesses:

ALnEN R. BEACH, MAReAREr JOHNSTON.

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